title: Immunohistochemical determination of thymidylate synthase in colorectal cancer--methodological studies.
abstract: With the aid of specific monoclonal antibodies, an immunohistochemical technique has recently been developed for the detection of intratumoral thymidylate synthase (TS). This technique can be applied to paraffin-embedded material suitable for retrospective studies. In order to examine this technique further, the TS enzyme activity of lysates from frozen-stored colorectal cancer (CRC) specimens were compared with their immunohistochemical TS staining intensity (arbitrarily graded from 0 to 3). A statistically significant correlation between these two methods on a total of 25 tumour specimens (P < 0.001) was observed. The staining intensity in different areas of 48 paraffin-embedded CRCs was examined. Sixty-seven per cent of the tumours were homogeneously stained (either grades 0-1 or 2-3), 33% showed a heterogeneity in TS staining. Increased TS expression correlated with more advanced Dukes' stage (P < 0.001). It is concluded that TS immunostaining intensity reflects TS enzyme activity in colorectal tumours and is well suited for paraffin-embedded material. The TS immunostaining pattern is heterogeneous in up to one-third of the tumours.
authors.affiliation: Department of Surgery, South Hospital Stockholm, Sweden.
authors.forename: D
authors.initials: D
authors.lastname: Edler
authors.forename: H
authors.initials: H
authors.lastname: Blomgren
authors.forename: C J
authors.initials: CJ
authors.lastname: Allegra
authors.forename: P G
authors.initials: PG
authors.lastname: Johnston
authors.forename: U
authors.initials: U
authors.lastname: Lagerstedt
authors.forename: I
authors.initials: I
authors.lastname: Magnusson
authors.forename: P
authors.initials: P
authors.lastname: Ragnhammar
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism*; D003110:Colonic Neoplasms / Q000201:enzymology* / Q000473:pathology; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D016612:Paraffin Embedding; D012004:Rectal Neoplasms / Q000201:enzymology* / Q000473:pathology; D012189:Retrospective Studies; D013940:Thymidylate Synthase / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; D013940:Thymidylate Synthase